Bai thực hành tuần 1

Thao tác treen dataset

data(trees)
d <- trees
str(d)
## 'data.frame':    31 obs. of  3 variables:
##  $ Girth : num  8.3 8.6 8.8 10.5 10.7 10.8 11 11 11.1 11.2 ...
##  $ Height: num  70 65 63 72 81 83 66 75 80 75 ...
##  $ Volume: num  10.3 10.3 10.2 16.4 18.8 19.7 15.6 18.2 22.6 19.9 ...
names(d) <- c('G','H','V')

Tới đây đã xong một số việc

head(d)
##      G  H    V
## 1  8.3 70 10.3
## 2  8.6 65 10.3
## 3  8.8 63 10.2
## 4 10.5 72 16.4
## 5 10.7 81 18.8
## 6 10.8 83 19.7
vol <- d$V
vol
##  [1] 10.3 10.3 10.2 16.4 18.8 19.7 15.6 18.2 22.6 19.9 24.2 21.0 21.4 21.3 19.1
## [16] 22.2 33.8 27.4 25.7 24.9 34.5 31.7 36.3 38.3 42.6 55.4 55.7 58.3 51.5 51.0
## [31] 77.0
vol15 <- vol[vol>15 & vol < 50]
vol15
##  [1] 16.4 18.8 19.7 15.6 18.2 22.6 19.9 24.2 21.0 21.4 21.3 19.1 22.2 33.8 27.4
## [16] 25.7 24.9 34.5 31.7 36.3 38.3 42.6
voll <- d[d$V < 15 |d$H < 60,]
voll
##     G  H    V
## 1 8.3 70 10.3
## 2 8.6 65 10.3
## 3 8.8 63 10.2
d$logV <- log(d$V)
d$logH <- log(d$H)
d$Tong <- d$G + d$H + d$V

cut(vol,4)
##  [1] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9]
##  [7] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9]
## [13] (10.1,26.9] (10.1,26.9] (10.1,26.9] (10.1,26.9] (26.9,43.6] (26.9,43.6]
## [19] (10.1,26.9] (10.1,26.9] (26.9,43.6] (26.9,43.6] (26.9,43.6] (26.9,43.6]
## [25] (26.9,43.6] (43.6,60.3] (43.6,60.3] (43.6,60.3] (43.6,60.3] (43.6,60.3]
## [31] (60.3,77.1]
## Levels: (10.1,26.9] (26.9,43.6] (43.6,60.3] (60.3,77.1]
table(cut(vol,4))
## 
## (10.1,26.9] (26.9,43.6] (43.6,60.3] (60.3,77.1] 
##          18           7           5           1

Bộ dữ liệu iric

data ("iris")
cut(iris$Sepal.Length, 4)
##   [1] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (5.2,6.1] (4.3,5.2]
##   [8] (4.3,5.2] (4.3,5.2] (4.3,5.2] (5.2,6.1] (4.3,5.2] (4.3,5.2] (4.3,5.2]
##  [15] (5.2,6.1] (5.2,6.1] (5.2,6.1] (4.3,5.2] (5.2,6.1] (4.3,5.2] (5.2,6.1]
##  [22] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2]
##  [29] (4.3,5.2] (4.3,5.2] (4.3,5.2] (5.2,6.1] (4.3,5.2] (5.2,6.1] (4.3,5.2]
##  [36] (4.3,5.2] (5.2,6.1] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2]
##  [43] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (4.3,5.2] (5.2,6.1]
##  [50] (4.3,5.2] (6.1,7]   (6.1,7]   (6.1,7]   (5.2,6.1] (6.1,7]   (5.2,6.1]
##  [57] (6.1,7]   (4.3,5.2] (6.1,7]   (4.3,5.2] (4.3,5.2] (5.2,6.1] (5.2,6.1]
##  [64] (5.2,6.1] (5.2,6.1] (6.1,7]   (5.2,6.1] (5.2,6.1] (6.1,7]   (5.2,6.1]
##  [71] (5.2,6.1] (5.2,6.1] (6.1,7]   (5.2,6.1] (6.1,7]   (6.1,7]   (6.1,7]  
##  [78] (6.1,7]   (5.2,6.1] (5.2,6.1] (5.2,6.1] (5.2,6.1] (5.2,6.1] (5.2,6.1]
##  [85] (5.2,6.1] (5.2,6.1] (6.1,7]   (6.1,7]   (5.2,6.1] (5.2,6.1] (5.2,6.1]
##  [92] (5.2,6.1] (5.2,6.1] (4.3,5.2] (5.2,6.1] (5.2,6.1] (5.2,6.1] (6.1,7]  
##  [99] (4.3,5.2] (5.2,6.1] (6.1,7]   (5.2,6.1] (7,7.9]   (6.1,7]   (6.1,7]  
## [106] (7,7.9]   (4.3,5.2] (7,7.9]   (6.1,7]   (7,7.9]   (6.1,7]   (6.1,7]  
## [113] (6.1,7]   (5.2,6.1] (5.2,6.1] (6.1,7]   (6.1,7]   (7,7.9]   (7,7.9]  
## [120] (5.2,6.1] (6.1,7]   (5.2,6.1] (7,7.9]   (6.1,7]   (6.1,7]   (7,7.9]  
## [127] (6.1,7]   (5.2,6.1] (6.1,7]   (7,7.9]   (7,7.9]   (7,7.9]   (6.1,7]  
## [134] (6.1,7]   (5.2,6.1] (7,7.9]   (6.1,7]   (6.1,7]   (5.2,6.1] (6.1,7]  
## [141] (6.1,7]   (6.1,7]   (5.2,6.1] (6.1,7]   (6.1,7]   (6.1,7]   (6.1,7]  
## [148] (6.1,7]   (6.1,7]   (5.2,6.1]
## Levels: (4.3,5.2] (5.2,6.1] (6.1,7] (7,7.9]
table(cut(iris$Sepal.Length,4),iris$Species)
##            
##             setosa versicolor virginica
##   (4.3,5.2]     39          5         1
##   (5.2,6.1]     11         29        10
##   (6.1,7]        0         16        27
##   (7,7.9]        0          0        12